Grading excavator



Nov. 11 1924.

E. L. COBLE GRADING EXCAVATOR Filed Aug. 23. 1923 3 Sheets-Sheet l Nov. 11 1924. 1,515,459

. E. L. COBLE GRADING EXGAVATOR Filed Aug. 25 1923 3 Sheets-Sheet 2 Nov. 11 1924. 1,515,459

' E. L. COBLE GRADING EXCAVATOR.

Filed Aug. 23. 1923 3 Sheeis-Sheet 5 Patented Nov. ll, 1924.

GRADING EXoAvAToR.

Application filed August 23, 1923; Serial No: 658,964.

Toall'whom it may concern:

Be it known that I, ERNEST L. CoBLn, a citizen of the United States, residing at Alliance, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in Grading Excavators, of which the following is a specification.

The object of this invention is to provide an apparatus specially adapted for use in grading the site of an oil storage tank or other circular structure. The work of grading the site of an oil storage tank is now generally performed by hand labor and is exceedingly slow and costly, besides lacking in uniformity of result, and the primary object of my invention is to provide an apparatus which may be set up upon the site ofthe tank and economically operated to grade the site so that an even level surface will be provided for the foundation. Another object of the invention is to provide a machine which will operate upon the entire length of a radius of the tank and may be easily shifted about the center of the contemplated tank as the grading progresses so that the work will be performed rapidly and will be uniform in its results, while the cost will be very materially less than is the case when the work is done by hand labor. Another object of the invention is to provide an apparatus which may be adjusted to the diameter of the intended structure, and a still further object is to provide an apparatus by which the soil removed from one point may be deposited at another point where the surface is lower than the desired. grade or the removed earth may be otherwise disposed of. Another object of the invention is to provide means whereby the excavating member will be prevented from throwing dirt back upon the portion of the site which has been graded," and a further object of the invention is to so mount the apparatus that it may be easily adjusted to the portion of the site which has not been graded. Other incidental objects of the invention will appear in the course of the following description.

In the accompanying drawings, which illustrate one embodiment of the invention,

Figure 1 is a plan view of the apparatus in position for operation;

Fig. 2 is a rear elevation ofthe same;

Fig. 3 is an enlarged transverse section on the line 33 of-' Fig. 1;

Fig. 4 is a similar View on the line4-4 of Fig. 1;

Fig. 5 is anenlarged planvi'ew of-the dc livery end of the apparatus;

Fig. 6 is a central longitudinal section of Fig. 9 is a detail edge view of the partsshown in- Fig. 8, and

Fig. 10 is an enlarged detail section shew ing a different form of excavator blade.

In the practice of my invention, a portion of the site is graded by'hand so as to accommodate two tracks, 1 and 2, whichare" disposed concentric with the center of the site and are designed to support the central and outer end' portions of the apparatus.- The inner track 1 is flat and smooth upon its upper surface, while the outer track 2 is provided centrally with rack teeth 3, as shown, the purpose of the teeth appearing hereinafter. At the center of the site, I locate a platform 4 which may be ofan'y convenient or preferred construction and is anchored pivotally so that it may readily turn in a horizontal plane as the work'proceeds. This platform is secured rigidly to the inner end portion of the frame, and a motor 5 of any convenient type is'secured upon the platform, such motorbeing illustrated in a conventional manner in the accompanying drawings and being preferably a vertical internal combustion engine. The main frame of the apparatus is constructed in sections which are adapted to be connected end to end in alinement, and as many of these sections may be employed as is necessary in any given case and determined by the diameter of the tank to be erected. The construction of oil storage tanks has been standardized to such an extent that they are built upon diameters which are multiples of'five feet and they range in radius from five feet to siXty feet so that an apparatus which includes six sections of main frame and working elements each five feet long may be readily arranged to grade the site of any contemplated tank. The inner end of the innermost section includes standards or posts 6 secured rigidly upon the outer edgeportion of the platform 4 and connected at their upper ends by a cross bar or bridge piece 7 which may constitute the top member of a hanger 8. Upon the said bridge piece 7 I erect a frame 9 providing a bearing at its upper end for a drive shaft 10, the said shaft being alined with the drive shaft of the motor, as indicated most clearly in 2, and being equipped with a sprocket gear 11 which may be operatively engaged with or disengaged from the motor shaft by a clutch 12 of any preferred type. The excavator shaftis journaled in a bearing 13 furnished by the lower end of the hanger 8, and a sprocket gear 14L is cured upon the inner end of the said shaft to be driven through a chain 15 trained about the sprockets 11 and 14, as shown most clearly in Fig. 3. A chain tightener 16 may be provided upon the frame to maintain the tension of the chain 15 in an obvious manner, and, to provide an additional support for the drive shaft 10 so that it will run steadily and evenly. I may provide an additional supporting frame or bracket 17 erected upon the inner section of the main frame and providing a bearing for the outer end of the drive shaft. Secured rigidly to and extending outwardly from the bridge piece or cross bar 7 at the ends of said member are parallel bars 18 which have their outer ends secured rigidly to a cross bar or yoke member 19, the ends 20 of which are projected laterally beyond the said parallel bars 18 and are grooved on notched, as indicated at 21. Secured rigidly to the under side of the cross bar 19 and depending therefrom adjacent the bars 18 are vertical bracing bars or hangers 22, and between the standards 6 and the said hanger bars 22, side bars .43 extend to further brace the structure and impart rigidity to the same, the ends of the bars 23 being rigidly secured to the respective members 6 and 22, as will be readily understood. I also provide diagonal bracing rods 24: which have their opposite ends secured to the bridge piece 7 and the cross bar 19, respectively, and further strengthen the structure so as to resist spreading of the same and enable it to withstand the strains to which it is subjected. The outer side or edge of the cross bar 19 is provided substantially in the plane of the bars 18 with lugs or projections 25 which are adapted to lit in recesses or notches 26 formed in the inner end cross bar 27 of the next adjacent outer section of the frame so that the sections may be readily brought into alinement, and this construction is repeated through all thesections, each section having a cross bar 27 atits inner end provided with the recesses or notches 26 and provided at its outer end with a cross bar 19 having the lugs 25 to engage the corresponding or mating recesses in the next outer section. Truss rods 28 are secured at their inner ends to the upper ends of the standards 6 and have their outer end portions seated in the grooves 21 in the outer extremities of the extensions 20 of the cross bar 19. The truss rods 28 are provided with eyes or hooks or otherwise constructed to engage mating eyes 29 on the alined sections of the truss rods, which arrangement is carried throngs the structure to the outer end of the main frame and the intermediate sections of the truss rods are equipped with turnbuckles 30 so that the truss rods may be placed under tension to maintain the several sections in close engagement at their ends and supplement the top and side bars 18 and 23 in maintaining a rigid structure. The cross bar or yoke member 19 at the center of the main frame is equipped with standards or side members 31 which correspond to the side members 6 in form but are forked or otherwise constructed at their lower ends to provide bearings for rollers 32 having smooth peripheries and adapted to run upon the track 1 to support the structure and facilitate its movement toward the ungraded ground as the work progresses. The cross bar or yoke member at the outer end of the outermost section has secured thereto the depending standards or side members 33 which correspond to the standards 31 in all respects, but instead of smooth periphery rollers these side members 23 carry pinions 34 which are adapted to run upon the track 2 and engage the rack teeth 3 thereon. The axle of the rear pinion M is extended outwardly beyond the side member 83, as shown at 85, and a ratchet wheel 36 is secured upon the said extended axle. Fitted loosely upon the axle for pivotal movement thereon is a hand lever 37 having its lower portion forked, as shown at 38, to span the ratchet wheel 36, and a double pawl 39 is mounted within the fork 38 so as to engage the wheel 36 and impart rotation thereto upon oscillation of the lever. The pawl 39 being double-ended, the wheel 36 may be rotated in either direction as may be desired, and it will be understood, of course, that the rotation of the said wheel is transmitted through the axle 35 to the gear wheel so that the said wheel is caused to travel. on the rack 3 and thereby shift the outer end of the main frame in order that the ground-engaging members may be fed forward as the work progresses.

The excavator is of the helical type and comprises a shaft or axle 10 having a spiral blade 41 wound about the same. The axle 4:0 is preferably tubular so as to possess the requisite strength without excessive weight and it is, of course, made in sections corresponding in length to the sections of the main frame. The sections of the excavator are coupled together by solid coupling sections 42 which have their ends secured within the ends of the hollow or tubular axle and are journaled in the bearings provided at the lower ends of the several hangers 8. The innermost coupling shaft section 42 carries the sprocket gear 14 so that, when the motor is operating, the excavator shaft will be rotated and the spiral blade 41 will be caused to out into the surface of the ground and remove a layer of soil and simultaneously feed the said soil to the de livery end of the apparatus. A back plate 43 is carried by the main frame and has its lower end portion curved forwardly, as shown at 44, so as to fit closely to the blade of the excavator and also to the surface of the ground whereby the passage of dirt back of the excavator onto the graded surface will be prevented. The back plate 4-3 is coterminous with the main frame and is likewise constructed in sections. The upper edge of the plate is disposed adjacent the top members of the main frame and its intermediate portion is secured to a longitudinal bar 45 which is extended from end to end of the frame and is rigidly secured to cross pieces 46 provided in the several sections above the excavator, as shown in Figs. 3 and 4. It will be readily noted that the cutting edge of the helical blade ll works close to the surface of the back plate and the lower edge of the said plate is straight and disposed in proximity to the lowest point of the blade. As a result, when the machine is shifted forwardly after a period of cutting, the lower edge of the back plate will serve as a scraper to remove all slight unevennesses which may have been left by the spiral blade. At its outer end, the back plate or guard is reduced vertically and has its lower portion extended, as shown at 47, so that it will prevent the loose soil from working back to a point where it cannot be taken up by the elevator 48. The elevator 48 is of the endless chain bucket type and is carried within a frame 49 which is disposed adjacent the outer end of the main frame so that the elevator will be in alinement with the excavator, the lower end of the frame 49 being pivotally mounted upon a shaft 50 which constitutes the driving shaft of the elevator and is journaled in the end members of the main frame. Upon the said shaft 50 is secured a beveled gear 51 which meshes with a similar gear 52 on the outer end of a transmission shaft 53, the said shaft and the adjacent end of the shaft 50 being mounted in a bracket 54L which is secured upon the adjacent extremities of the side bars 23 of the main frame. On the in nor end of the shaft 53 is a sprocket gear 55, around which is trained a chain 56 whereby the sprocket is operatively con nected with a sprocket 57 secured on the inner end ofthe excavator shaft. Motion is thus imparted to the elevator from the excavator shaft and the transmission gearing is disposed in compact form and so arranged that it will not interfere with the passage of the dirt nor with the operation of any of the other parts. To the upper end of the elevator frame is secured a bail or loop 58 from which a cable 59 extends to a drum 60 mounted in suitable bearing posts 61 upon the main frame at about the center of the same. The drum is carried by a shaft 62 extending through the said bearing posts and equipped at its rear end with a crank or other operating handle 63. A ratchet wheel 64 is secured upon the shaft 62 adjacent one bearing post 61 and a dog 65 is mounted upon the said post in position to engage the said ratchet and thereby prevent retrograde movement of the drum so 9 dump the dirt beyond the site of the intended tank so that an embankment will be formed around the tank when the operations have been finished.

The edge of the excavating blade may be smooth and will then operate very efliciently in most instances. It sometimes happens, however, that exceedingly hard clay is encountered and in that event it is desirable to provide the cutting edge of the excavator with teeth, as shown at 67 in Fig. 10, and it will be understood that, if the nature of the soil requires, some sections of the excavator may have a smooth continuous cutting edge and other sections have the toothed edge.

The tracks 1 and 2 may be made in sections to facilitate the placing of the same in position and, if preferred, only sections of the track may be employed, one section being taken up and shifted ahead of another section as the grading progresses, it being possible to efiect a saving in the cost of installation in this manner. The tracks should be provided with broad under sides or bases so that they will not tend to cut into the graded portions of the foundation. The platform 4 having been pivotally anchored at the center of the site and the tracks having beenplaced in position, the frame including as many sections as may be necessary to grade a space of the required radius is brought into position and the several sections rigidly connected so that the rollers supporting the frame sections will rest upon the proper tracks, and it will be understood, of course, that the side bars 23 and the top bars 18 have their ends overlapped so that they will serve as connections between the sections as well as reinforcements for the separate sections. The parts having been properly assembled and adjusted, the motor is started and the spiral excavating blade will thereupon cut into the surface of the soil to the depth required to reduce it to the required grade, the soil being fed to the outer end of the frame sinmltaneously with its removal from the surface. At the outer end of the frame, the soil will be delivered to or taken up by the buckets of the elevator and will be then transferred to the wagon 66 or deposited upon an embankment or otherwisedisposed of at points outside the site of the tank. W'lien the soil has been removed at one point to the desired depth, the lever 37 is manipulated, as above de scribed, so as to rotate the rear wheel 3 and thereby effect travel of the frame and the parts supported thereby forwardly upon the tracks about the anchor of the platform a as a pivot. The travel of the apparatus may be effected without stopping the action. of the excavator so that the operation of clearing and grading the site will be continuously performed.

My apparatus is very simple and is compactly arranged, while the construction of the frame is such that it will possess great strength and durability. The apparatus may be very easily set up at any point of operation and when the work has been completed it may be very readily disassembled and transported to another place of use. By employing my improved machine, the work of grading a site may be accomplished very rapidly and with a minimum amount of labor so that a very material economy in the cost of preparing a site for the erection of a tank will be effected.

aving thus described the invention, what is claimed as new is:

1. An apparatus for the purpose set forth comprising a frame, means for mounting said frame for pivotal movement about one end, a motor at the pivotal end of the frame, an excavator extending loiwitudinally of the frame and operable to excavate material below the frame and deliver the excavated material at the free end of the frame, and means for operatively connecting the excavator with the motor.

2. An apparatus for the purpose set forth comprising a frame anchored at one end for pivotal movement about said end, a spiral excavator extending longitudinally of the frame and operable to excavate material below the frame and deliver the material at the outer free end of the frame, means at the pivotal end of the frame for actuating said excavator, and a relatively stationary back plate extending longitudinally of the frame from end to end thereof in proximity to the excavator.

3. In an apparatus for the purpose set forth, the combination of a frame mounted for pivotal movement about one end, an excavator extending longitudinally of the frame, a relatively stationary back plate secured upon the frame in proximity to the excavator and having its outer end extended beyond the outer end of the excavator, and an elevator mounted upon the outer end of the frame adjacentthe extended outer end of the back plate.

fin apparatus for the purpose set forth comprising a main frame mounted at one end for pivotal movement, tracks extending under the frame at the center and the outer end therefor, the outer track being provided with rack teeth on its upper side, rollers carried by the frame at the center thereof travel upon the inner track, toothed wheels carried by the frame at the outer end thereof to ride upon the outer track and engage the rack teeth thereon, means cooperating with one of said toothed rollers to effect rotation of the same and cause travel of the frame upon the tracks, and an excavator extending longitudinally of the frame.

5. In an apparatus for the purpose set forth, a. main frame comprising similar sections disposed end to end and having coun terpart constructions at their meeting ends, means for coupling said sections together, a sectional spiral excavator mounted upon the frame and extending from end to end thereof, and means mounted on the frame for ac tuating the excavator.

6. An apparatus for the purpose set forth comprising a main frame consisting of a plurality of sections arranged end to end, each section having a cross bar at one end provided with notches and at its other end with a cross bar having lugs to engage in the notches in the mating cross bar at the opposed end of a meeting section, one cross bar upon each section having its ends extended laterally from the section, truss rods secured to the ends of the outermost sections and engaged with the said laterally extended ends of the cross bars, means for placing the truss bars under tension, means for coupling the sections rigidly together, and an excavator carried by the sections.

7. An apparatus for the purpose set forth comprising a main frame consisting of sections arranged end to end, each section including cross bars at its ends and vertical frame members depending from said cross bars, parallel bars secured to the said cross bars at the ends of the same, side bars secured to the vertical frame members, said side bars and parallel bars serving as means for coupling the sections together, diagonally disposed brace rods upon the several sections, truss rods engaged with the cross bars upon the several sections, means for putting the truss bars under tension, and an excavator extending longitudinally of the several sections.

8. An apparatus for the purpose set forth comprising a frame mounted for pivotal movement about its inner end, and means mounted on the frame for excavating ma terial below the frame and feeding the excavated material toward the free end of the frame.

9. An apparatus for the purpose set forth comprising a frame supported at one end for pivotal movement about said end, arouate tracks concentric with the pivotal end of the frame rolling supports mounted on the frame and arranged to run on the tracks, manually operable means associated With some of said rolling supports to rotate the same and eflect pivotal travel of the frame, and an excavator mounted longitudinally on the frame and operable to remove soil from below the frame and deliver it at the outer free end of the same.

In testimony whereof I aflix my signature.

ERNEST L. COBLE. [1,. s.] 

